Dispatching Vehicles Considering Multi-lifts of Quay Cranes

Abstract

Abstract.To improve the ship operation in automated container terminals, it is important to schedule different types of handling equipment to operate synchronously. For example, a vehicle with container receiving and lifting capabilities is used to transport containers from a storage yard to a vessel and vice versa, while a triple quay crane (QC) can handle up to three 40-ft containers simultaneously. This paper discusses the manner in which vehicles should be assigned to containers to support such multi-lifts of QCs by using information about the locations and times of deliveries. A mixed-integer programming model is introduced to optimally assign delivery tasks to vehicles. This model considers the constraint imposed by the limited buffer space under each QC. A procedure for converting buffer-space constraints into time window constraints and a heuristic algorithm for overcoming the excessive computational time required for solving the mathematical model are suggested. A numerical experiment is conducted to compare the objective values and computational times of the heuristic algorithm with those of the optimizing method to evaluate the performance of the heuristic algorithm.

Heuristic Algorithms for Constructing Transporter Pools in Container Terminals

“…The main focus of this study was to reduce the empty trip times of YTs with minimum delays for ship operations. Nguyen and Kim [3] proposed a vehicle dispatching method for supporting QCs with multilifting capabilities.…”

“…Studies carried out by authors so far include dual-commandcycle operations of a QC [1], dispatching transporters for minimizing empty travels of transporters [2], dispatching vehicles for QCs with multilifting capabilities [3], look-ahead dispatching single-load vehicles [5], dispatching ALVs [17], and dispatching vehicles with uncertain operation times [19]. Although many studies have been done on the management of transporters in container terminals, the authors could find no study that developed a method for optimally constructing pools of the transporters, which is the main contribution of this paper.…”